Interference bands in decays of doubly-charged Higgs bosons to dileptons in the minimal type-II seesaw model at the TeV scale

Abstract

The dileptonic decays of doubly-charged Higgs bosons H±± are investigated in the minimal type-II seesaw model with one Higgs triplet Δ and one heavy Majorana neutrino N1 at the TeV scale. We show that the branching ratios B(H±±→lα±lβ±) depend not only on the mass and mixing parameters of three light neutrinos νi (for i=1,2,3), but also on those of N1. Assuming the mass of N1 to lie in the range 200 GeV–1 TeV, we figure out the generous interference bands for the contributions of νi and N1 to B(H±±→lα±lβ±): |sinθi4sinθj4|∼10−8–10−5, where θi4 and θj4 measure the strength of charged-current interactions of N1. We illustrate some salient features of the interference bands by considering three typical mass patterns of νi, and stress that it is very difficult to distinguish the type-II seesaw model from the triplet seesaw model in such a parameter region at the Large Hadron Collider.